In the field of lighting the passenger compartment of a motor vehicle, it is known to use conventional filament bulbs as light sources. However, in the automotive field as in other fields, light-emitting diodes (LEDs), which are semiconductor components, are being used increasingly frequently as light sources, notably for reasons of consumption. Either monochromatic lighting is then produced or a set of LEDs emitting red, green and blue light is used to obtain white light or light of any other color at will as a function of the control signal applied to the LEDs.
However, if it is required to control the light spectrum of the lighting and if it is moreover required that this spectrum be stable over time, i.e. notably with temperature, that necessitates electronic control circuits that require space to be available, notably for the optical and electrical inputs/outputs, which commensurately reduces the space available inside the vehicle, space always being an important parameter for a motor vehicle.